Not real sure about tire designations for different brands, but I drive a 4X4 truck, with A/T tires. The 'A' stands for All-Terrain. My wife's car has M&S/T tires. That stands for Mud & Snow. M/T stands for Mud tires, and if my thinking is correct(and yours) H/T stands for Highway tires.
I have Michelin LTX M/S load range E on my Pleasureway. When I put these tires on, I went with the 'E' range tires, because they are made for heavier loads, thus the van doesn't sway as much in side winds or uneven roads.